1. Field of the Invention
The present invention relates to a mechanism for feeding photosensitive material, such as photographic paper, to an exposure station within a printing station of an auto-printer and, more particularly, to such mechanism useful with the exposure station loaded with a greeting card kit.
2. Description of the Related Art
A conventional auto-printer generally includes stations, such as a printing station and a processor station, wherein photographic paper is continuously fed from its roll to the printing station and exposed to an image recorded on original film, such as negative film in the exposure station.
Recently, a new type of photocard has come into wide use, which is a postcard or the like having a photographic picture printed on a part of its rear side and a greeting message printed in the margins surrounding the printed photographic picture. Sometimes the exposure station contained within the printing station of the auto-printer is loaded with the greeting card kit in order to print the photocard in the auto-printer. As will be apparent from FIG. 8 of the accompanying drawing, the greeting card kit 1 is adapted to receive a lith plate 2 withdrawably inserted thereinto and the lith plate 2 is formed with a picture zone exposure window 2a and a lith film mount frame 2b. The greeting card kit 1 is loaded with a continuous strip of photographic paper 3 in readiness for exposure and further feeding.
To perform operation of printing by the auto-printer loaded with the greeting card kit 1, the lith plate 2, carrying a lith film 4 having a greeting message or the like recorded thereon and mounted on the lith film mount frame 2b, is inserted into the greeting card kit 1 from the outside, as shown by FIG. 9. Then, photographic paper 3 is exposed to the characters or the like recorded on the lith film 4 followed by exposing photographic paper 3 to the picture zone of the lith film 4 through the picture zone exposure window 2a.
After photographic paper 3 has been initially loaded, the forward end of photographic paper 3 in the form of a roll is guided downward by a pair of guide rollers (not shown) provided above the greeting card kit 1 into this. When photographic paper 3 is fed to the greeting card kit 1 containing therein the lith plate 2, there is an apprehension that the forward end of photographic paper 3 might float off from the feed path as the forward end of photographic paper 3 reaches the picture zone exposure window 2a of the lith plate 2 because no guide member is provided for the forward end. If photographic paper 3 is further fed without correcting such condition, the forward end may be possibly caught by the lower edge of the picture zone exposure window 2a and photographic paper 3 may be prevented from being smoothly loaded. Also, when photographic paper 3 is fed into the greeting card kit 1 having the lith plate 2 withdrawn therefrom, photographic paper 3 may often be caught within the greeting card kit 1 since the greeting card kit 1 has no guide member therein.
To avoid this inconvenience, there has been proposed the arrangement, as shown by FIG. 9, according to which a pair of rails 5 extend in parallel to and between upper and lower guide plates 1a, 1b of the greeting card kit 1, i.e., in parallel to the direction in which the lith plate 2 is slidable. The rails 5 extend through respective guide holes 6a of a loading plate 6 so that this loading plate 6 may be slidably moved along the rails 5. Appropriate helical springs 7 are provided around the respective rails 5 and the loading plate 6 is fed to these helical springs 7 in the proximity of the respective guide holes 6a. In this manner, the loading plate 6 is set under the biasing force of the helical springs 7 to a position at which the loading plate 6 is laid upon photographic paper 3 as the lith plate 2 is withdrawn.
Accordingly, in order to load the greeting card kit 1 with photographic paper 3, an operator may withdraw the lith plate 2 from the greeting card kit 1 to set the loading plate 6 upon the feed path for photographic paper 3 so that the forward end of photographic paper 3 may be guided by the loading plate 6 and smoothly fed downward without floating off from the feed path.
Referring to FIG. 9, insertion of the lith plate 2 causes its forward end to push the loading plate 6 against the biasing force of the helical springs 7 until the loading plate 6 retracts from the position at which the loading plate 6 has been laid upon the feed path for photographic paper 3. Thus, the photographic paper 3 is ready to be exposed without any interference.
However, the above-mentioned greeting card kit, according to the prior art, includes relatively many members, such as the slidable loading plate 6 and the helical springs 7, leading to the correspondingly increased number of parts. With such arrangement of the prior art, therefore, it is often difficult to minimize the size, as well as the weight of the greeting card kit 1, to simplify the manufacturing process, and to reduce the manufacturing cost.
In view of this problem, it is an object of the invention to provide a photosensitive material feed mechanism for the exposure station of an auto-printer that is improved in a manner that, for initial loading of the photographic paper, the forward end thereof can be reliably guided and smoothly fed.
After a predetermined number of printings have been completed, the lith plate 2 is withdrawn from the greeting card kit for exchange of the lith film 4 even though photographic paper 3 remains loaded therein. However, reinsertion of the lith plate 2 may often cause trouble such that the forward end of the lith plate 2 is caught by a side edge of photographic paper 3 and thereby obstruct the desired smooth operation.
In view of this problem, it is another object of the invention to provide a photosensitive material feed mechanism for the exposure station of an auto-printer that is improved so that both the insertion and the withdrawal of the lith plate can be smoothly performed even if the photographic paper remains loaded therein.